Addressing your points slightly out of order…

the incompatability here could be equally seen to be a criticism of Live Comment Preview

I see your point. Yes.

Also complaining that it doesn’t work with Textile is a bit much! Exactly how would you expect these two to work together (assuming the current wordpress architecture) ?

No, I don’t really expect these to work together. They are competing for the same niche. I should have pulled Textile out of this list and addressed it separately. Sorry for the confusion.

My real point is that both Textile and MarkDown are similar in that they each expect all of the other plugins to bend to their will.

“basic” markup provided by Wordpress is neither HTML, nor a subset.

Yes, that’s true. As I play some more, with MarkDown turned off, this fact is becoming more relevant and visible to me, which is unfortunate.

Whether they are directed at the Markdown plugin, or the Wordpress architecture as a whole, I’m not sure your ‘plays well with others’ criticisms are entirely valid.

I think that our positions here are actually very close.

I think that there is an implicit architecture design decision in WordPress that the database stores HTML-ish formatting, and that MarkDown is bad in failing to conform.

I think that your position is that there could be a range of formats that could be used, including MarkDown, and that if there is a sufficient plugin soup to choose between, you should be able to find a set of plugins that provide a solution to your requirements.

I want to propose a new architecture based on what I got from your message.

There should be sufficient meta-information stored by WordPress, to allow (i) a plug-in to decide whether or not it can read a format and, preferably, (ii) conversions between the formats.

Let Live Comment Preview either say “Hey, I don’t recognise this format” or, even better, “please get me the HTML version of this comment”.

Let Textile and MarkDown co-exist, with each post saying “I’m in MarkDown encoding” or “I’m in Textile encoding” (or I’m HTML-ish, or pure HTML)

Hmmm… sounds like a job for XML. I’m scaring myself.

So, I am kind of agreeing with you. If the WordPress architecture assumes HTML-ish format, MarkDown doesn’t play well. But, if we agree that tools like MarkDown and Textile are key parts of a blog, then the WordPress architecture should be enhanced to provide explicit mechanisms for different plugins to communicate in a common (set of?) encoding.

I totally agree that wordpress’ integration of markdown is flawed, and said as much in a previous comment. As you say, it’s an architectural issue. If Markdown to be a first-class citizen in wordpress, instead of merely a plugin, then maybe it might play well with others?

Whether they are directed at the Markdown plugin, or the Wordpress architecture as a whole, I’m not sure your ‘plays well with others’ criticisms are entirely valid. Does it matter that you can’t use Live Comment preview with Markdown? Surely it matters more whether you can solve the general problem of comment previews? (eg AJAX Comment Preview, which does AFAICT work with Markdown). Put another way, the incompatability here could be equally seen to be a criticism of Live Comment Preview.

Also complaining that it doesn’t work with Textile is a bit much! Exactly how would you expect these two to work together (assuming the current wordpress architecture) ?

Disagree also with your analysis about which layer Markdown belongs in. The justification here seems to be to allow other tools to work with the generated HTML instead of the Markdown source. Again, this seems to be architecting with a specific technological solution in mind (eg Semagic, which I presume is a blog editor), rather than to best solve the given problem. My blog editor MarsEdit parses Markdown quite nicely, so I for one want Markdown source stored in the blog database and NOT generated HTML.

Bear in mind that blog tools that assume the source text is HTML formatted are already broken, because the “basic” markup provided by Wordpress is neither HTML, nor a subset.

Ah, I know what you’re thinking. ‘Did he use six bullet points, or only five?’ Well, to tell you the truth, in all this excitement, I’ve kinda lost track myself…